Lesquereux, Leo: Coal flora of the carboniferous formation in Pennsylvania and throughout the United States. Description of the coal flora of the carboniferous formation in Pennsylvania and throughout the United States : Vol I. 1. cellular cryptogamous plants, fungi, thalassophytes. 2. vascular cryptogamous plants, calamariae, filicaceae (ferns.) ; Vol II. 1. lycopodiaceae. [...] / Leo Lesquereux. 1879-1880 : 1(1879-). Harrisburg : published by the board of commissioners for the second geological survey, 1880